Resilient shank stiffener



March 26, 1929. J, A BRQGAN 1,706,478 I RESILIENT SHANK STIFFENER Filed Dec. 3, 1924 Patented Mar. 26, 1929.

UNITED STATES 1,706,478 P'Arsr Price;

JAMES a. 'BnoeAN, or LAWRENCE, mnssnonnsnr'rs, ASSIGNOR roxun rnn' SI-IOYE;

MACHINERY CORPORATION, or rn rnns'on, NEW messy, n oonronarion or new JERSEY.

RESILIEN'I' SHANK s'rrrrnnnn.

This invention relates to, resilient arch supporting shank stiffeners commonly known as spring shanks and to boots and shoes'provided with shank; stiffeners of this type; V

preserve the normal longitudinal curvature of the shank portions of shoe soles without destroying the flexibility of the-soles. Accordingly, such stiffeners, as usuallyconstructed, are curved lengthwise to conform to the longitudinal arch of the shank portions of the boots or shoes in which the stiffeners are incorporated and the stiffeners are" made sufficiently flexible to yield readily so as not to prevent the desiredv flexing of the soles at the shank. Thus, by preserving the arched formation of the shank .of theshoe, a resilient shank stiffener is 'capable of affording a substantial amount of loop has engaged the'outer sole'ofthe shoe, the stiffener, does not become entirely rigid supportfor thearch of the foot although, being capable of yielding readily,, such a stiffener will not interfere with the natural flexure of the foot in walking.

Heretofore, spring shanks, so-called,have been constructed and arranged so as to yield to such a degree that not only will they pervm'it the entire flattening of the archv of the sole and the completecollapse of the longi-' tudinalarch of the foot, but, because of the excessive flexing of the stiflener after extended periods of use, the stiffeners are liable to break at or near the middle of the arch, thus rendering them useless and mak ing it necessary to have "the shoe repaired.

In view of the foregoing, one object of the present invention is to provide an improved resilient arch supporting shank stiffener which will be flexible enough to respond readily to normal changes in, foot .1 arch curvature but;which'nevertheless, when incorporated vin a shoe, will, be incapable of excessive bending or flexing, and thus will insureagainst undue flattening of. the arch of the sole or the arch of the, foot, and which will not be liable to break but mayi- V I derstood from the following description,'refbe relied upon to perform their intended 1 functions throughoutthe -life of the shoe.

To theaccomplishment ofthis object, and,

in accordance with one feature of the invention, the improved shank stiffener consists of a longitudinally arched strip having, substantially midway between itsv ends, a portion offset or bent transversely-of the strip an ameiint less than theJheight of the arch,

Resilient shank stiffeners are intended to,

,videdwitha shank stiflener'such that shown in Fig; 1-; r

for co-operation with the sole of a shoein which the stiffener is incorporatedv to limit of a U-shaped loop which extends'entirely across the strip. Being offset from the strip anamount less than the height of the arch the loop will act as a stop which, by ten-- gagement with .the outer sole, will prevent the strip from'flattening-beyond a predetermined maximum amount and thus will ac- V .complish the desirable results above re,-

ferred to. Not only w'illltheloop prevent excessive flattening of the longitudinal arch of the strip in such a way asto tend to weaken the strip or to permit entire col lapse of the arch ofthe shoe, or the arch of thefoot, but even after the bottom of the but is still capable of yielding at eitherside of the loop; The yielding of the strip underthese circumstances, however, is distrib-" uted over portions of the strip removed from the middle portion thereof and has no tendto a shoe it may beinserted between the.

,soleswithout being secured to either, orit may be secured by tacks, vrivets or the like at one end-it willprobably. be desirable to secure it at the heel end. The' unsecured end of the stiffenerwill then be free to slide endsof the'stifl'enerare firmly secured by rivets to the outer sole of the shoe, the flexing of the strip under pressure will be 'perat either or at both ends; If securedfonly mitted by the looped portion thereof, the

sides of which will be'capable of approaching each other to permit the strip to flatten."

, The features of the invention will be. un-

erence beinghad to the accompanying drawings, in which Fig. 1 is a perspective View of the im-C 3 proved shank stiffener; I

' extent.

Fig. 3 is a perspective view of an alternative form of shank stiffener.

Referring first to Fig. 2 of the drawings, a welt shoe is therein illustrated comprising an upper 4, an innersole 6, and an outer sole able the stiffener and tl'ie'shank portion of the innersole to yield readily under the weight of the wearer of the shoe the shank stiffener 12, asillustrated, consists of a resilient metallic strip and in order to prevent excessive flexing of the strip the strip is formed, substantially midway between its ends, with a transverse bend or loop 14 designed to function as a stop positively to limit the straightening or collapsing movement of the stiffener so as to prevent the arch of the foot from being flattened beyond a predetermined As will be apparent from an exa'minationof Fig. 2, the loop is bent at right angles to the length of the stiffener and is open at the convex side of the strip. The base or closed end of the loop 1 1 is spaced 7 from the outer sole a sufficient distance to permit the arch of the foot to straighten only to a limited extent to avoid injury to the foot. After such straightening of the arch has been effected, the base of the loop 14 en- I gages the outer sole and positively prevents further flattenin or ieldin of the central b y b portion of the shank stiffener and correspending further collapse of'the arch of the foot. The loop 14: may be substantially U- sha ed as shown in Fi 's. 1 and 2 or it ma be of any suitable form such, for example,

as that shown at 16 in Fig. 3. The opposite sides of the loop are spaced apart so that,in case both ends of the strip are firmly secured to the sole of the shoe, as shown in Fig. 1, the stiffener willstill be resilient inasmuch as the opposite sides of the loop may approach each otherunder pressure tending to flatten out the stiffener. After the loop 14;

has been depressed into engagement with the outer sole,'however, the portions of the shank stiffener at either side of the central loop are capable of yielding more or less independently of each other, under excessive pressure, for the purpose of cushioning the sole of the foot from the effects of any sudden orunusual shock such as might result from running or jumping. The material of the stiffener may, however, be made of such stiffness that, under ordinary conditions, little if any resiliency will be apparentafter the loop 14 has seated upon the outer sole.

Thus, after the stiffener has yielded sufficiently to cushion the shocks such as those produced by ordinary walking, the stifiener may become substantially unyielding so long as the pressure of the foot continues to be maintained steadily against it so that substantially'a positive support for the arch of the foot is then afforded. It may also be found desirable to form more than a single loop in the stiffener, thereby further increasing the resiliency of the stiffener. As shown,

the stiffener is provided at its oppositeends with apertures 18 for the reception. of suit.- able fastening means, such as one or both of the rivets 20 shown in Fig. 2, thereby firmly.

anchoring the stiffener in place at one end or at both ends as may be desired. Inasmuch as the loop is located substantially midway between theends'of the stiffener it will not be necessaryto make any change in the construction of the shoe to receive theloop and the presence of the loop will not alter in any way the usual shape of the shoe bottom.

If, as shown, the stiffener is riveted at both ends to the shoe sole it will be-e-vident that the opposite sides of the loop may approach each other under pressure tendingto flatten or straighten the longitudinal arch of the stiffener, thus permitting the stiffener to flex or straighten even though its ends are anchored to the shoe. Furthermore, if both ends of the stiffener are anchored neither end 7 will rub across the sole and thus injury to the sole from such rubbing action is avoided. To prevent the forward extromity'of the stiffener from i'nyurmg the outer solein case it is preferred not to anchor the forward end of the stiffener in a given instance, this end may be formed with a slight upward curve, such as shown at 22 in Fig. 1, this construction insuring that the end of the stiffener will not-dig into the outer sole in case it rubs somewhat over the surface of the sole as the stiffener changes its shape while the shoe is being worn.

Having described my inventionjwhat I claim as new and desire to secure by Letters Patent of the United States is:

1. An arch supporting shank stiffener comprising an elongated longitudinally arched strip having alaterally offset loop substantially midway between its ends the opposite sides of which'areconstructed and arranged to yield in a generalv direction lengthwise of the strip under pressure tend-- ing to flatten the strip.

2. A resilient shank stiffener consisting of a longitudinally arched strip having an integral transversely bent portion of the full width of the strip 'and located substantially longitudinal arch of the midway between its endsf'or increasing the resiliency of the stiffener.

3. A shank stiffener consisting of a resilie'nt strip arched longitudinallylto conform" ends, the loop being shorter than the height of arch of' the stiffener and adapted to engage the sole to limit the straightening of the longitudinal arch of the stiffener.

' 5. A shoe comprising inner and outer soles spaced apart at the shank, a shank stiffener longitudinally curved to conformto the longitudinal arch of the lnnersole and located in the, space between the lnner and outer soles, said stiffener being formed with a transverse loop opening toward the innersole and spaced from the outer sole for im-- parting resiliency to the stiffener and limiting the straightening of the longitudina curve of the shank stiffener.

6. In a shoe having inner and outer soles, a longitudinally arched shank stiffener loeated between the soles and having an integral looped portion bent at right anglesto the length of the stiffener to adapt the sides of the loop to approach each'other under pressure tending to straighten the arch of the stiffener, the closed end portion of the loop being located at the concave side of the stifiener to function as a stop to prevent excessive straightening of the stiffener, and

rivets extending through the outer sole and through the opposite ends of the stiffener for rigidly securing the stiffener to the outer sole.

7. An arch supporting shank stiffener con- I sisting of a longitudinally arched strip having a portion offset transversely of thestrip strip may be straightened when the stiffener is incorporated in a shoe, the amount of the offset being less than the height of the. arch of the strip.

8. A shank stiffener comprising'a longitudinally arched resilient strip transversely bent'between its ends to provide an. integral resilientstop projecting from the concave side of the stiffener strip for engagement with the sole of'a shoe in which the stiffener is to be incorporated to permit the longitudinal arch of the stiffener to be straightened only to a limited extent.

'9. A resilient shank conform to the longitudinal arch of a foot and having an integral U-sh-aped bend offset from the concave side of the stiffener an amount less than the normal height of the arch for limiting theextent to which the stiffener is capable of straightening under pressure applied to'the convex side of the stiffener. v

l0. A longitudinally arched stiffener havstiffener arched to A ing a resilient transverse loop between its ends, the loopbeing shorter than the height of the arch of the stiffener and adapted for engagement withthe sole of a shoe in which the stiffener is to be incorporated to limit the straightening of the longitudinal arch of the stiffener.

11. A shoe comprising inner and outer soles, and an arched shank stiffener interposed between said soles, said stiffener being transversely bent substantially midway'between its ends to provide a stop for engagement with the outer sole to limit the straightening of the arch of the shank stiffener and having its opposite ends riveted to the outer sole. r

In testimony whereof I have signed my name to this specification.

" JAMES A. BROGAN. 

